The Problems of MgO-CaO Refrectories
Easy hydration has always been the core problem that hinders the popularization and application of magnesia calcium refractories. If the problem of easy hydration is not solved, the magnesia calcium refractories cannot be well popularized. The so-called hydration here does not only refer to hydration in production, but also includes hydration in storage, transportation and use. Under the existing process, it is very difficult to make the magnesia calcium refractory completely non hydrated.
So far, through the efforts of many researchers at home and abroad, great progress has been made in the hydration resistance of magnesia calcium refractories, but this problem has not been completely solved, and the hydration resistance is always a major topic. For magnesia calcium refractories, both MgO and Cao belong to face centered cubic structure in structure. The character constants of MgO and Cao are 4.2a and 4.8A respectively, and their coordination numbers are 6. Four molecules are contained in one cell. Compared with the radius of Mg2 +, the radius of Ca2 +is larger, and Mg2+can be completely surrounded by O2-, But Ca2+ is pushed out by O2-.